def _write_after(self) -> None:
super()._write_after()
self.fileobj.seek(self._fileobj_blocks_end_pos)
self.fileobj.truncate()
self.fileobj.write(
create_xz_index_footer(
self.check,
[(block.unpadded_size, block.uncompressed_size)
for block in self._fileobjs.values()],
))
def __init__(
self,
fileobj: IOAbstract,
check: int,
unpadded_size: int,
uncompressed_size: int,
) -> None:
self.length = uncompressed_size
self.fileobj = IOCombiner(
IOStatic(create_xz_header(check)),
fileobj,
IOStatic(
create_xz_index_footer(check,
[(unpadded_size, uncompressed_size)])),
)
self.reset()
def fileobj() -> BinaryIO:
# create xz raw data composed of many identical blocks
nb_blocks = 50
seed(0)
data = compress(randbytes(BLOCK_SIZE))
header = data[:12]
footer = data[-12:]
check, backward_size = parse_xz_footer(footer)
block = data[12 : -12 - backward_size]
records = parse_xz_index(data[-12 - backward_size : -12])
index_footer = create_xz_index_footer(check, records * nb_blocks)
return cast(
BinaryIO,
IOCombiner(
IOStatic(header),
*[IOStatic(block)] * nb_blocks,
IOStatic(index_footer),
),
)
def test_create_xz_footer_invalid_check() -> None:
with pytest.raises(XZError) as exc_info:
create_xz_index_footer(17, [])
assert str(exc_info.value) == "footer check"
def test_create_xz_footer(check: int, data: str) -> None:
assert create_xz_index_footer(check, [])[-12:] == bytes.fromhex(data)
def test_create_xz_index_invalid() -> None:
with pytest.raises(XZError) as exc_info:
create_xz_index_footer(1, [(73, 60), (0, 12), (56, 30)])
assert str(exc_info.value) == "index record unpadded size"
def test_create_xz_index(records: List[Tuple[int, int]], data: str) -> None:
assert create_xz_index_footer(1, records)[:-12] == bytes.fromhex(data)